Exhaust fan



, C. H. KEENEY EXHAUST FAN Filed Aug. l0.' 1925 a @ZM 3% Patented May 10, 19 27.

UNIT-ED STATES CHARLES H. KEENEY, OF'AVON, CONNECTICUT.

EXHAUST FAN.

Application filed August 10, 1926. Serial No. 128,442.

This invention relates to the construction of those exhaust fans which are designed to collect from machines and discharge into bins or to the atmosphere, grinding dust, granite dust, tumbling barrel dust, cement, shavings, chips and the other materials, polished or cut from stock during the process of manufacture, also for handling grain, smoke odors and acid fumes, in fact any material which it is .desired to transfer by air currents. The machine built according to this invention is particularly serviceable for transferring material which ordinarily subjects the fan to considerable destructive wear, as its suction inlet is adjacent to the discharge outlet, rather than central with the axis of the fan, whereby the material drawn in is immbdiately discharged without passing through the fan wheel or around the casing, and thereby eliminating destructive wear -on the casing and fan blades and preventing any clogging and unbalancing of the wheel. i

The object of the invention is to so arrange the suction inlet of an exhaust fan of this type, thatin a simple and cheap way the efficiency of operation of the fan is increased and the wear of the parts is greatly reduced.

In the embodiment of the invention illustrated this object is attained by locating the suction inlet at the side of a practically circular casing below the axis of the fan wheel and adjacent to the discharge outlet which is in the periphery of the casing,'the inlet opening being just in front ofthe discharge opening with ,relation'to the direction of rotation of the fan wheel. A deflector is arranged in the interior of the casing in continuation with the inlet and extending adjacent tothe path of the fan. in such position and of such shape that the air currents produced by the rotation of the fan cannot blow back into the inlet but will be caused to flow around the deflector and draw material in through the inlet and at once discharge it through the outlet. A shield is located across the lower part of the casing between the deflector and the fan to eliminate the possibility of any material striking or entering the fan as it passes from the inlet to the discharge.

In the accompanying drawings Fig. 1 shows a vertical section of a machine that embodies the invention, with the fan Wheel, shield, and a portion of the casing side plate which carries the inlet fitting, in side elevation. Fig. 2 is a view looking down with the casing, intake, deflector and fan wheel in section. Fig. 3 is a perspective view on larger scale of the .casing side plate which carries the inlet fitting and the deflector.

The casing of the machine has a circular peripheral wall 1, of sheet steel, with a tangential discharge outlet 2. Attached to the casing on one side is a plate 3' and on the other side is a plate 4, which plates are sheet steel and close the sides of the fan chamber. In the late 4 below the center of the casing and ad acent to the outlet is the inlet openingfi. Attached to the outside'of this plate around the inlet is the inlet fitting 6. The inlet opening is somewhat wider than it is high, extending toward the discharge opening. The inlet fitting is circular in cross section at its outer end, that is, the end to which the usual piping from the source of material to be collected is connected, and increases in width toward the outlet until it joins the side plate, at which locality the fitting is substantially oval in cross section and conforms to the inlet opening.

Attached to the inside of the side plate 4 and conforming to and surroundin a portion of the inlet opening is the de ector 7. This shield extends inward obliquely toward the path of the fan wheel from the side plate a considerable distance on the side of the inlet opening which is furthest from the outlet opening, and while conforming in cross section to the inlet opening, its end is cut off obliquely to the axis so that on the outlet side it is reduced to practically nothing. 3

The shield 8 is a plate of sheetmetal arranged across the lower part of the casing between the deflector and the fan path. The outer edge of the shield is out 01f at an angle.

The fan wheel illustrated has a. conical body 9 fastened to a hub 10. Substantially radial fan blades 11 are attached to the outer; face of this body and hub. The hub is fastened to the end of the shaft 12. This shaft extends through the center of the side plate 3 and is supported by suitable bearings 13 between which it carries a driving pulley 14 that is designed to be belted so as to turn the fan in the direction directed by the arrow on Fig. 1.

When the fan is rotated air is drawn in through the inlet and discharged through the outlet carrying with it the material to be conveyed. The deflector prevents the an currents produced by the fan from blowing back through the inlet and directs the conveyed material to the outlet. As the air passes around the tapering deflector and past its end a powerful suction effect is produced at the inlet. As the inlet fitting tapers toward the outlet and the air currents are directed by the tapering deflector toward the outlet the flow is such that all material drawn in is immediately delivered directly to the outlet with considerable velocity and without passing through the wheel or being carried around the casing. Furthermore the shield prevents any of the solid material from being carried into the fan. This not only increases the efliciency of the machine for the material is immediately discharged from it, but it also eliminates the abrading wear on the casing and fan blades whlch results in those machines which are so designed as to carry the solid material around.

with the fan from the inlet to the discharge.

The invention claimed is 1-- 1. An exhaust fan comprising a substantially circular casing, a fan wheel rotatable within the casing, said casing having a tangential discharge opening and an inlet opening through one side eccentric to the fan wheel axis and adjacent to the discharge opening, and means fixed within the casing for deflecting material from the inlet to the dischar e, whereby material drawn into the casing %y the rotation of the fan wheel is immediately dischar ed and not carried around by the fan w eel.

2. An exhaust fan comprising a substantially circular casing, a fan wheel rotatable within the casing, said casing having a tangential discharge opening and an inlet opening through one side eccentric to the fan wheel axis, and a. deflector within the casing, said deflector extending inward from and conforming to a portion of the inlet opening and directing material therefrom toward the discharge opening.

3. An exhaust fan comprising a s1ibstantially cylindrical casing, a "fan wheel rotatable within the casing, said casing having a tangential discharge opening and an inlet opening through one side eccentric to the fan axis and adjacent to the discharge opening, and a deflector within the casing, said deflector conforming in cross section to a portion of the inlet opening and extending inward further on the side distant from the discharge opening than on the side nearest the discharge opening.

4. An exhaust fan comprising a substantially circular casing, a tap wheel rotatable within the casing, said casing having a tangential discharge opening and an inlet opening through one side eccentric to the fan Wheel axis and adjacent to the discharge opening, an intake fitting attached to the side of the casin and conforming to the inlet opening, an a deflector extending inward from and conformin to a portion of the inlet opening, said deflector having its inner end cut ofl obliquely to the axis of the deflector and opening toward the discharge opening.

5. An exhaust fan comprising a substantially circular casing, a fan wheel rotatable within the casing, said casing having a tangential discharge opening and an inlet open ing through one side below the axis of the fan wheel and adjacent to the dischar e opening, and a shield extending across t e lower part of the casing between the inlet opening and the fan path to prevent the,

passage of material from the inlet opening to the fan path.

6. An exhaust fan comprising a substantially circular casing, a fan wheel rotatable within the casing, said casing having a tangential discharge opening and an inlet opening through one side eccentric to the fan wheel. axis and adjacent to the discharge opening, and a deflector within the casing and conforming to a portion of the inlet 0 ening, said deflector extending inward o liquely from the inlet opening toward the fan path.

7. An exhaust fan comprising a substantially circular casing, a fan wheel rotatable within the casing, said casin having a tangential discharge opening an an inlet opening through one side below the axis of the fan wheel'and adjacent to the discharge opening, a deflector within the casing and conforming to a portion of the inlet opening, said deflector extending oblique] inward from the inlet opening towar the tan path, and a shield arranged across the lower part of the casing opposite the inlet opening and'between the deflector andthe fan path.

CHARLES H. KEENEY. 

